35... f7f5 Black is preparing g6-g5 or Kg7-h6-h5. 36. h2h4 Prophylaxis against g6-g5. 36... e4e3 This is a difficult move for me, as I'd be afraid of giving the d3-square to the king. The computer (and Gukesh) aren't so scared. 37. d2e2  37... e8e7 